Precatalyzed epoxy resin compositions containing a relatively low equivalent weight epoxy resin and a phosphonium compound have been employed to prepare relatively high molecular weight resins by reacting with a polyhydric phenol. Such compositions are subject to storage over prolonged periods of time and in many instances, the composition loses its catalytic activity after such storage at elevated temperatures, which results in an epoxy resin having a significantly different epoxide content than expected from a ratio of epoxy to phenolic hydroxy groups as well as detrimental increases in viscosity.
These problems have been overcome by the present invention which pertains to a precatalyzed epoxy resin which is relatively stable at elevated temperatures.